So first things first. My grandfather was a nazi. I'm not proud of it, but I'm not ashamed of it. I barely knew the guy.
My grandmother passed a couple of years ago. Among her things there was a couple of albums and a few pictures from my grandfather's time in Nasjonal Samling (National Union/Unity, Norway's nazi party) and NS Arbeidstjeneste (voluntary work force) during WW2. Also a couple of shoulder distinctions from the NS Arbeidstjeneste. No one in my family seemed to care for them so I snatched them up. I mean, I don't think this side of WW2 history has been documented very well. I don't condone what he did, but there's got to be some historic value to this right? Could you direct me to someone who might be interested?
TL;DR: Grandpa was a nazi. What to do with pictures?
If that were my collection, I would scan everything for my own purposes and then donate the collection (with an electronic copy of the scans) to an archive. There must be a university or museum/historical society in Oslo or elsewhere that would be interested in this material. You might want to ask /r/Norway for suggestions.
Scandinavian alignment with German nationalism and the Nazi party is not well understood, and many wish to see it obscured. Your material is of value and needs to be preserved. For a look at a similar dynamic in Sweden, see my brief essay, Nazis, Trolls and the Grateful Dead: my mentor's mentor was a Nazi sympathizer, resigning from a pro-German organization on the day that Denmark and Norway were invaded.